The Arabidopsis nucleoporin NUP1 is essential for megasporogenesis and early stages of pollen development

Abstract

Key message

Loss-of-function of nucleoporin NUP1 in Arabidopsis causes defect in both male and female gametogenesis. Its ovules are arrested during meiosis, and its pollen grains are aborted at mitosis I.

Abstract

Nuclear pore complex (NPC) plays crucial roles in nucleocytoplasmic trafficking of proteins and RNAs. The NPC contains approximately 30 different proteins termed nucleoporins (NUPs). So far, only a few of plant NUPs have been characterized. The Arabidopsis NUP1 was identified as an ortholog of the yeast NUP1 and animal NUP153. Loss-of-function of NUP1 in Arabidopsis caused fertility defect; however, the molecular mechanism of this defect remains unknown. Here, we found that both male and female gametogenesis of the nup1 mutants were defective. nup1 ovules were arrested from the meiosis stage onward; only approximately 6.7% and 3% ovules of the nup1-1 and nup1-4 mutants developed up to the FG7 stage, respectively. Pollen development of the nup1 mutants was arrested during the first mitotic division. In addition, enlarged pollen grains with increased DNA content were observed in the nup1 mutant. RNA-sequencing showed that expression levels of genes involved in pollen development or regulation of cell size were reduced dramatically in nup1 compared with wild type. These results suggest that NUP1 plays an important role in gametogenesis.

Notes

Acknowledgements

We thank The Nottingham Arabidopsis Stock Center (NASC) for the T-DNA insertions, John Innes Centre for the pGREENII0229 vector. We thank Ruming Liu and Yajuan Wan for technical assistance in the use of confocal and cell cytometry equipment, respectively. This work was supported by grants from the National Science Foundation of China (31570247, 91417308, and 31460453); the Natural Science Foundation of Tianjin (no. 14JCYBJC41200).

Funding

This work was supported by grants from the National Natural Science Foundation of China (31570247, 91417308, and 31460453).

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